Theoretical investigations on 4,4′,5,5′‐tetranitro‐2,2′‐1H,1′H‐2,2′‐biimidazole derivatives as potential nitrogen‐rich high energy materials

The ―NH2, ―NO2, ―NHNO2, ―C(NO2)3 and ―CF(NO2)2 substitution derivatives of 4,4′,5,5′-tetranitro-2,2′-1H,1′H-2,2′-biimidazole were studied at B3LYP/aug-cc-pVDZ level of density functional theory. The crystal structures were obtained by molecular mechanics (MM) methods. Detonation properties were evaluated using Kamlet–Jacobs equations based on the calculated density and heat of formation. The thermal stability of the title compounds was investigated via the energy gaps (∆ELUMO − HOMO) predicted. Results show that molecules T5 (D = 10.85 km·s−1, P = 57.94 GPa) and T6 (D = 9.22 km·s−1, P = 39.21 GPa) with zero or positive oxygen balance are excellent candidates for high energy density oxidizers (HEDOs). All of them appear to be potential explosives compared with the famous ones, octahydro-1,3,5,7-tetranitro-1,3,5,7-tetraazocane (HMX, D = 8.96 km·s−1, P = 35.96 GPa) and hexanitrohexaazaisowurtzitane (CL-20, D = 9.38 km·s−1, P = 42.00 GPa). In addition, bond dissociation energy calculation indicates that T5 and T6 are also the most thermally stable ones among the title compounds. Copyright © 2014 John Wiley & Sons, Ltd.